<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<select>
    <option value="0">--选择省份--</option>
    <option value="1">河南</option>
    <option value="2">江苏</option>
</select>
<select>
    <option >--选择市--</option>
</select>
<script type="text/javascript" src="js1/jquery-1.11.1.js"></script>
<script type="text/javascript">
    var jilian=[["--请选择市--"],["郑州","洛阳","平顶山"],["南通","海安"]]
    var c
    $("select:first").change(function () {
        var html;
        $("select:first").each(function (i,obj) {
           c=($(obj).val())
            console.log(c)
        })
      for (var a=0;a<jilian[c].length;a++) {
            html += "<option>" + jilian[c][a] + "</option>"
           console.log(jilian[c][a])
        }
        $("select:last").html(html);
    })
</script>
</body>
</html>